diff options
author | Aaron Sierra <asierra@xes-inc.com> | 2018-10-12 23:35:03 +0300 |
---|---|---|
committer | Jon Mason <jdmason@kudzu.us> | 2018-11-01 04:20:05 +0300 |
commit | fc5d1829f9bf3d8275322727c0e9a8baf268b7c6 (patch) | |
tree | 882b53242929fc4cc4ff3736ac52fcc5de1f0782 /drivers/ntb | |
parent | 846429bc998f4c42d9961c139ce82d0f76a51d35 (diff) | |
download | linux-fc5d1829f9bf3d8275322727c0e9a8baf268b7c6.tar.xz |
NTB: transport: Try harder to alloc an aligned MW buffer
Be a little wasteful if the (likely CMA) message window buffer is not
suitably aligned after our first attempt; allocate a buffer twice as big
as we need and manually align our MW buffer within it.
This was needed on Intel Broadwell DE platforms with intel_iommu=off
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers/ntb')
-rw-r--r-- | drivers/ntb/ntb_transport.c | 86 |
1 files changed, 63 insertions, 23 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index c643b9cf750b..3bfdb4562408 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -194,6 +194,8 @@ struct ntb_transport_mw { void __iomem *vbase; size_t xlat_size; size_t buff_size; + size_t alloc_size; + void *alloc_addr; void *virt_addr; dma_addr_t dma_addr; }; @@ -672,13 +674,59 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw) return; ntb_mw_clear_trans(nt->ndev, PIDX, num_mw); - dma_free_coherent(&pdev->dev, mw->buff_size, - mw->virt_addr, mw->dma_addr); + dma_free_coherent(&pdev->dev, mw->alloc_size, + mw->alloc_addr, mw->dma_addr); mw->xlat_size = 0; mw->buff_size = 0; + mw->alloc_size = 0; + mw->alloc_addr = NULL; mw->virt_addr = NULL; } +static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw, + struct device *dma_dev, size_t align) +{ + dma_addr_t dma_addr; + void *alloc_addr, *virt_addr; + int rc; + + alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size, + &dma_addr, GFP_KERNEL); + if (!alloc_addr) { + dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n", + mw->alloc_size); + return -ENOMEM; + } + virt_addr = alloc_addr; + + /* + * we must ensure that the memory address allocated is BAR size + * aligned in order for the XLAT register to take the value. This + * is a requirement of the hardware. It is recommended to setup CMA + * for BAR sizes equal or greater than 4MB. + */ + if (!IS_ALIGNED(dma_addr, align)) { + if (mw->alloc_size > mw->buff_size) { + virt_addr = PTR_ALIGN(alloc_addr, align); + dma_addr = ALIGN(dma_addr, align); + } else { + rc = -ENOMEM; + goto err; + } + } + + mw->alloc_addr = alloc_addr; + mw->virt_addr = virt_addr; + mw->dma_addr = dma_addr; + + return 0; + +err: + dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr); + + return rc; +} + static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, resource_size_t size) { @@ -710,28 +758,20 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, /* Alloc memory for receiving data. Must be aligned */ mw->xlat_size = xlat_size; mw->buff_size = buff_size; + mw->alloc_size = buff_size; - mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size, - &mw->dma_addr, GFP_KERNEL); - if (!mw->virt_addr) { - mw->xlat_size = 0; - mw->buff_size = 0; - dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n", - buff_size); - return -ENOMEM; - } - - /* - * we must ensure that the memory address allocated is BAR size - * aligned in order for the XLAT register to take the value. This - * is a requirement of the hardware. It is recommended to setup CMA - * for BAR sizes equal or greater than 4MB. - */ - if (!IS_ALIGNED(mw->dma_addr, xlat_align)) { - dev_err(&pdev->dev, "DMA memory %pad is not aligned\n", - &mw->dma_addr); - ntb_free_mw(nt, num_mw); - return -ENOMEM; + rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align); + if (rc) { + mw->alloc_size *= 2; + rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align); + if (rc) { + dev_err(&pdev->dev, + "Unable to alloc aligned MW buff\n"); + mw->xlat_size = 0; + mw->buff_size = 0; + mw->alloc_size = 0; + return rc; + } } /* Notify HW the memory location of the receive buffer */ |